<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>css学习</title>
    <style>
        .one {
            border: 1px, green, solid;
            height: 200px;
            width: 500px;
            padding: 10px;
            margin: auto;
        }
        .two1 {
            border: 1px, blue, solid;
            height: 50px;
            width: 200px;
            margin: 20px;
        }
        .two2 {
            border: 1px, blue, solid;
            height: 50px;
            width: 200px;
            margin: 10px;
        }
    </style>
</head>
<body>
    <div class="one">
        <div class="two1">div000</div>
        <div class="two2">div111</div>
    </div>
    <div class="one">div222</div>
    <div class="one">div333</div>
</body>
</html>